App mode do not follow system title bar setting

[UbioZur]

Description

Web apps do not follow the 'use system title bar' setting.
The apps show the integrated title bar and not the system title bar.

Steps to Reproduce

1. Disable the title bar on your system (so if the setting is working, then no title bars should be shown.
2. enable in brave the setting for 'use system title bar'
3. open an installed web app, and look that there is a title bar displayed despite the fact that there shouldn't be any.

Actual result:

the web app have the brave included title bar, with the title, buttons, menu etc...

Expected result:

No title are shown as it does for brave itself.

Reproduces how often:

100% reproducible.

Brave version (brave://version info)

Brave | 1.52.126 Chromium: 114.0.5735.133 (Official Build) unknown (64-bit)
Revision | fbfa2ce68d01b2201d8c667c2e73f648a61c4f4a-refs/branch-heads/5735@{#1270}
OS | Linux

Version/Channel Information:

• Can you reproduce this issue with the current release? yes
• Can you reproduce this issue with the beta channel? Don't know
• Can you reproduce this issue with the nightly channel? Don't know

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? no
• Does the issue resolve itself when disabling Brave Rewards? no
• Is the issue reproducible on the latest version of Chrome? N/A

Miscellaneous Information:

[EXtremeExploit]

Still happens on version 128.1.69.153
WM: AwesomeWM on X11
distro: Arch Linux

[EXtremeExploit]

I found a workaround.

• Install the app like you would normally would
• Edit the .desktop file that brave created in .local/share/applications, it will have a weird name, you can change it
• in Exec change it to something like Exec=/opt/brave-bin/brave --profile-directory=Default --app="https://web.whatsapp.com"
• Of course change the URL to the actual website you want to visit
• Now that .desktop file will open a window without the browser title bar, if that doesnt work try deleting the StartupWMClass line if it exists